import java.util.Scanner;

public class PrimeNumber {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int i = 2;
        boolean a = true;
        while(i <= n/2) {
            if(n%i == 0) {
                a = false;
                break;
            }
            i++;
        }
        if(a) {
            System.out.println(n+"是素数");
        } else {
            System.out.println(n+"不是素数");
        }
        sc.close();
    }
}
